I have a mild left lumbar scoliosis (pelvic obliquity), but my left leg is also longer, so a shoe lift on my right doesn't help me. what can i do?

Give it time: Pelvic obliquity and scoliosis are not related. The pelvic tilt is due to the leg length difference. This should be corrected with a shoe lift, but your body has adapted to the difference. Give the lift some time. Scoliosis is a different problem. It could be compensatory due to the pelvic tilt, or it may be a separate problem. Discuss with your doctor and therapist.